>Some form of a webDAV, possibly 'skinned', comes to mind, as
>shared rights and ACL are well defined and readily supported;
>Clients in every Linux, OS/X or Windows release in active
>support [also on my iTouch and related portible devices], so
>far as I know; server side is trivial; uses the 'universal
>firewall traversal protocol on TCP/80 (plaintext) and TCP/443
>(TLS) ;)
Is it actually called "skinned"? Sounds like what I need...